- Chill a cocktail glass by filling it with ice water and setting it aside.
- In a cocktail shaker, add the fresh mint leaves and lightly muddle to release their oils.
- Add absinthe, fresh lime juice, elderflower liqueur, and simple syrup into the shaker.
- Fill the shaker with ice and shake vigorously for about 15 seconds.
- Empty the ice water from the cocktail glass and strain the mixture into the glass.
- Garnish with a fresh mint leaf on top.